Coal burning stoker



Aug. 2%, was. H; B, @NLEY 2,011,852

COAL BURNI NG STOKER Filed Dec. 51, 1952 ,uNirso gen-E5 Patented Aug. 20, 1935 I 011,852 '1 coat, BURNlING SITQKEB Harold B; mmasc umnschit-assi ns t i Columbus Metal Products Inc Columhuaohio,

v a coniora ionof Ohio Application December 31, 1932, Serial'No. 5493 w ZCIaims. (o1.--1 o;i ,4

This invention relates to coal stokers for domes-' tic furnaces and is particularly directed to that type known as under feed stokers'employing crushed or pulverized fuel which i's depo'sited-in a hopper and fed upwardly into a retort positioned wi-thinthe furnace.

The primary object of the invention is to provide means'whereby should the stokergas or dust bacl; through the fuel hopper such gas or dust will be withdrawn from "thehoppen'be'fore' having a' chance of escaping into the furnace room.

Another objectcf the inventionis-to make use of the-blower, employed in connection with the stoker, for withdrawing "the gas" or dust' which may find its wayback through the stekermechanism or the fuel therein.'

10, 1934, there is shown an arrangement wherein the driving mechanism, blower and the fuel hopper are all positioned within a housing having a V I perforated top wall constituting the air'inlet'for lthe blower. Although this arrangement is highly practical from an operating'stanclpoint, the addle tion of the housing adds cost as well as size to-the apparatus which, in some cases meets with certain objections and particularly from a sales standpoint. It is therefore also aniobject of the present invention to reducethe cost of the apparatus by the elimination of the housing above re-' ferred to but yet retain the practical feature of having the blower serve as means for withdrawing the objectionable gases which may be present in the fuel hopper. c

For a further understanding of the invention, reference is to be had to the following description and the accompanying drawing, wherein:

Fig. 1 is a vertical sectional'view of a portion of a furnace showing the stoker comprising the present'invention operatively connected therewith;

Fig. 2 is a detail sectional View taken on the numeral I designates the usual form of furnace in which is positioned the. retort 2' throughwhich a partof this inventign; such parts op i'dfi l s'una sli ht ressi ehea wit fuel is fed upwardly frornthefuel conveying con duit'e'connecting the fuel hopper' i. 'Th e feeding of the fuelthrough the conduit may be accqrnplishedby such means as a serew. conveyor (not shown) positioned' longitudin of the conduit d'd ve by airowrm gh 5 ar anged at: teri'or or the furnace andhopper, v For delivering a o t rt iqu in iih mn t hi t k 13 1; QUQt'fi i 'l d h gh. W 1 the air" is"'forced by "a blowerunit .1 also driven r ng motor nis ha ismi t p r ciilar fiii of retort, conveyor. and moto r mechanismfi g are" only ferred to in a'general'xnannerr Due t i ff iliefbio ki ii i the combustioni'zone of'the furnacaga'ses and iii; have a tendency at times to flow 'backwardly through the fuel conduit and into the hopper from which-it may find its exit into the furnace room. To overcome this objectionable condition, 7

the blowerunit i is'provided adjacent its inlet 3 with a-shallow pan-like shield 9 which is'diaghas its side wall I? spaced from the inlet opening 8 of the blower to provide an air receiving space M, which is open at its upper end so that air may enter therein and'be directed to the inlet sideof the blower -Carried by the shield and arranged upon the side of the'wall Isis "a duct I5 which extends longitudinally ofthe shield and has its upper end attached to the wall 12 and in registration with an opening 16 formed therein which opening is also in communication with a branch duct H formed with a corner'of the hopper. 'The duct branches l5 and H form a continuous conduit having its lower end positioned adjacent the inlet 8 of the blowerand its upper end'term'inating at.a point approximately even with the top of the fuel receiving chamber of the hopper. Overlying the upper end of the duct branch I I and-spaced a dis-. tance above the same is a plate I8 which serves to keep coal particles from falling into the duct duning the filling of the hopper and which clue to its spaced position fromthe duct provides an inlet therefor which opens inwardly towards the interior of the hopper.

Closing the upper end of the hopper is a hood !9 having a hinged lid 20 carried by its upper wall covering the filling opening formed therein. The lid 20 is formed with louvers 2| providing openings or entrances for air into the hopper.

' By this arrangement, it will be seen that when the stoker is in operation, with the blower unit running, the major portion of the air for the blower will be drawn through the open end of the intake provided by the shield 9. This will create an induced draft in the duct branches .15 and I1 and causea slight air current through the louvers 2| and across the fuel body in the hopper which air current will serve to withdraw any as or dust present in the fuel hopperand'prevent the same from finding its exit into the furnace room. As. the blower receives its major air supply exterior of the hopper, the induced air draft interior and across the top of the hopper is therefore slight and no suction is created upon the fuel body. However this weak air current is of suflicient strength to carry with it i motor-driven blower provided with-an air intake opening in the'side wall of its casing, a fuel hops per having an open'top for the reception of solid fuel, a. conduit for transferring fuel-from the lower portion of said lhopper to said retort, a vented closurefor the open top of said hopper, an openended shield communicating at its lower end with the air intake of saidblower and having its open upper end terminated contiguous to said hopper, a

conduit disposed internally of said hoppen said conduit being open. at its upper end tocommunicate with thespace normally present between the fuel contained within the hopper and said closure, and a second conduit joined with the lower end of the first conduit and extending in angular relation with respect thereto, said second conduit being disposed within the confines of said shield and having its lower end terminated adjacent to the air intakeopening of said blower, whereby during the operation of said blower, the passage of air through said shield will produce a mild induced draft in said conduits to withdraw volatiles from the upper region of said hopper.

, 2. In automatic stoker mechanism, a retort. a motor-driven blower'provided with an air intake opening in the sidewall of its casing, a fuel hopper having an open top for the reception of solid 'fuel, a conduit for transferring the fuel from the lower portion of a said hopper to said retort, a

7 tween the fuel contained within the hopper and said'closure, and a second conduit joined with the lower end of the first conduitand extending in angular relation with respect thereto, said second conduit being disposed within the confines of said shield and having its lower end terminated adjacent to the-air intakeopening of said blower,

whereby during. the operation of said blower, the passage of air through said shield will produce a HAROLD B. DONLEY. 

